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US4939691A Expired / Lapsed US ⏱️ 0.0 years remaining

Static random access memory

Assignee: Toshiba Corp
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Filing: 1988-10-20
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Granted: 1990-07-03
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Expires: 2008-10-20
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Abstract

Abstract In a static random access memory, when data is written into said plurality of memory cells, a write enable signal is set at a low level, and after the data write is completed, the write enable signal is set at a high level. In response to a level change of the write enable signal from a low level to a high level, a pulse generator generates a pulse signal in "1" level and with a given pulse width. In response to this pulse signal, a first MOS transistor is turned on to short paired bit lines. This pulse signal turns on second and third MOS transistors. Then, the potentials on the paired bit lines are pulled up to a power source potential. As a result, of the two bit lines, the bit line which has been set at a low potential immediately after data is written, is charged. A pulse extension/inverting circuit extends the pulse width of the pulse signal generated by a pulse generator by a given time period, and inverts a logical state of the pulse signal. During a period that the first MOS transistor shorts the bit lines to place the equal potentials on the bit lines, the pulse signal φWRD output from the pulse extension/inverting circuit is kept in "0" level. During this period, therefore, the output data of two AND gates is "0" level irrespective of the sensed data from a read circuit and the supply of the sensed data from the read circuit to a data output circuit is stopped.

Inventors

  • 👤 Shigeto Mizukami
  • 👤 Makoto Segawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 04:08
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/34; G11C11/40; G11C11/41; G11C11/413; G11C11/417; G11C11/419

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 277 words
A static random access memory comprising: paired bit lines; a plurality of static memory cells connected in parallel between said paired bit lines; a write means coupled with said bit lines and for supplying write data to said bit lines; a read means coupled with said bit lines and for sensing data on the basis of the potentials on said bit lines; a data output means coupled with said read means and for outputting the data sensed by said read means; a control signal terminal supplied with a write control signal, when data is written into said plurality of memory cells, said write control signal being set at a first level, and after the data write is completed, said write control signal being set at a second level; a pulse generating means for generating a pulse signal with a given pulse width in response to a level change in said write control signal from the first level to the second level; a pulse extension means for extending the pulse width of the pulse signal generated by said pulse generating means; a first switching element connected between said bit lines, said first switching element being turned on and off by said pulse signal; second and third switching elements respectively connected between said bit lines and applied points of power source potentials, said second and third switching elements being turned on and off by said pulse signal; and a gate circuit connected between said read means and said data output means and for controlling the supply of sensed data from said read means to said data output means according to the pulse signal extended by said pulse extension means.
Claim 2
Dependent Claim 277 words
A static random access memory comprising: paired bit lines; a plurality of static memory cells connected in parallel between said paired bit lines; a write means coupled with said bit lines and for supplying write data to said bit lines; a read means coupled with said bit lines and for sensing data on the basis of the potentials on said bit lines; a data output means coupled with said read means and for outputting the data sensed by said read means; a control signal terminal supplied with a write control signal, when data is written into said plurality of memory cells, said write control signal being set at a first level, and after the data write is completed, said write control signal being set at a second level; a pulse generating means for generating a pulse signal with a given pulse width in response to a level change in said write control signal from the first level to the second level; a pulse extension means for extending the pulse width of the pulse signal generated by said pulse generating means; a first switching element connected between said bit lines, said first switching element being turned on and off by said pulse signal; second and third switching elements respectively connected between said bit lines and applied points of power source potentials, said second and third switching elements being turned on and off by said pulse signal; and a gate circuit connected between said read means and said data output means and for controlling the supply of sensed data from said read means to said data output means according to the pulse signal extended by said pulse extension means.
Claim 3
Dependent Claim 53 words
A static random access memory according to claim 1, in which said first switching element is connected between paired data lines through said paired bit lines and a switching element, and said second and third switching elements are respectively connected between said paired data lines and the applied points of power source potential.
Claim 4
Dependent Claim 20 words
A static random access memory according to claim 1, in which said first to third switching elements are MOS transistors.
Claim 5
Dependent Claim 59 words
A static random access memory according to claim 1, in which said control signal terminal is supplied with a write enable signal, when data is written into said plurality of memory cells, said write enable signal being set at a low level, and after the data write is completed, said write enable signal being set at a high level.
Claim 6
Dependent Claim 71 words
A static random access memory according to claim 1, in which said pulse generating means includes an odd number of inverting circuits connected in tandem, the first stage of said inverting circuits receiving the write control signal supplied to said control signal terminal and an AND gate supplied with the output signal from the final stage of said inverting circuits and the write control signal supplied to said control signal terminal.
Claim 7
Dependent Claim 63 words
A static random access memory according to claim 1, in which said pulse extension means includes an even number of inverting circuits connected in tandem, the first stage of said inverting circuits receiving the pulse signal from said pulse generating means, and a NOR gate supplied with the pulse signal from the final stage of said inverting circuits and said pulse generating means.
Claim 8
Dependent Claim 40 words
A static random access memory according to claim 1, in which said gate circuit includes two AND gates coupled for reception with the complementary data output from said read means and the pulse signal extended by said pulse extension means.
Claim 9
Dependent Claim 57 words
A static random access memory according to claim 1, in which said pulse extension means extends the pulse width of the pulse signal generated by said pulse generating means by a time period from an instant that data is read out from one of said plurality of memory cells till said read means operates to complementary data.
Claim 10
Dependent Claim 51 words
A static random access memory according to claim 1, in which said pulse extension means extends the pulse width of the pulse signal generated by said pulse generating means, and inverts a logical state of the extended pulse signal with respect to the pulse signal generated by said pulse generating means.
Claim 11
Dependent Claim 393 words
A static random access memory comprising: paired bit lines; a plurality of static memory cells connected in parallel between said paired bit lines; paired data lines; first and second switching elements respectively connected between said paired bit lines and said data lines, said first and second switching elements being turned on and off by a column decode signal; a write means coupled with said data lines and for supplying write data to said data lines; a read means coupled with said data lines and for sensing data on the basis of the potentials on said data lines; a data output means coupled with said read means and for outputting the data sensed by said read means; a control signal terminal supplied with a write control signal, when data is written into said plurality of memory cells, said write control signal being set at a first level, and after the data write is completed, said write control signal being set at a second level; a pulse generating means for generating a pulse signal with a given pulse width in response to a level change in said write control signal from the first level to the second level; a pulse extension means for extending the pulse width of the pulse signal generated by said pulse generating means; a third switching element connected between said bit lines, said third switching element being turned on and off by said pulse signal generated by said pulse generating means; fourth and fifth switching elements respectively connected between said bit lines and applied points of power source potentials, said fourth and fifth switching elements being turned on and off by said pulse signal generated by said pulse generating means; and a sixth switching element connected between said paired data lines, said sixth switching element being turned on and off by said pulse signal generated by said pulse generating means; seventh and eighth switching elements respectively connected between said data lines and applied points of power source potentials, said seventh and eighth switching elements being turned on and off by said pulse signal generated by said pulse generating means; and a gate circuit connected between said read means and said data output means and for controlling the supply of sensed data from said read means to said data output means according to the pulse signal extended by said pulse extension means.
Claim 12
Dependent Claim 393 words
A static random access memory comprising: paired bit lines; a plurality of static memory cells connected in parallel between said paired bit lines; paired data lines; first and second switching elements respectively connected between said paired bit lines and said data lines, said first and second switching elements being turned on and off by a column decode signal; a write means coupled with said data lines and for supplying write data to said data lines; a read means coupled with said data lines and for sensing data on the basis of the potentials on said data lines; a data output means coupled with said read means and for outputting the data sensed by said read means; a control signal terminal supplied with a write control signal, when data is written into said plurality of memory cells, said write control signal being set at a first level, and after the data write is completed, said write control signal being set at a second level; a pulse generating means for generating a pulse signal with a given pulse width in response to a level change in said write control signal from the first level to the second level; a pulse extension means for extending the pulse width of the pulse signal generated by said pulse generating means; a third switching element connected between said bit lines, said third switching element being turned on and off by said pulse signal generated by said pulse generating means; fourth and fifth switching elements respectively connected between said bit lines and applied points of power source potentials, said fourth and fifth switching elements being turned on and off by said pulse signal generated by said pulse generating means; and a sixth switching element connected between said paired data lines, said sixth switching element being turned on and off by said pulse signal generated by said pulse generating means; seventh and eighth switching elements respectively connected between said data lines and applied points of power source potentials, said seventh and eighth switching elements being turned on and off by said pulse signal generated by said pulse generating means; and a gate circuit connected between said read means and said data output means and for controlling the supply of sensed data from said read means to said data output means according to the pulse signal extended by said pulse extension means.
Claim 13
Dependent Claim 20 words
A static random access memory according to claim 10, in which said first to eighth switching elements are MOS transistors.
Claim 14
Dependent Claim 59 words
A static random access memory according to claim 10, in which said control signal terminal is supplied with a write enable signal, when data is written into said plurality of memory cells, said write enable signal being set at a low level, and after the data write is completed, said write enable signal being set at a high level.
Claim 15
Dependent Claim 71 words
A static random access memory according to claim 10, in which said pulse generating means includes an odd number of inverting circuits connected in tandem, the first stage of said inverting circuits receiving the write control signal supplied to said control signal terminal, and an AND gate supplied with the output signal from the final stage of said inverting circuits and the write control signal supplied to said control signal terminal.
Claim 16
Dependent Claim 63 words
A static random access memory according to claim 10, in which said pulse extension means includes an even number of inverting circuits connected in tandem, the first stage of said inverting circuits receiving the pulse signal from said pulse generating means, and a NOR gate supplied with the pulse signal from the final stage of said inverting circuits and said pulse generating means.
Claim 17
Dependent Claim 40 words
A static random access memory according to claim 10, in which said gate circuit includes two AND gates coupled for reception with the complementary data output from said read means and the pulse signal extended by said pulse extension means.
Claim 18
Dependent Claim 57 words
A static random access memory according to claim 10, in which said pulse extension means extends the pulse width of the pulse signal generated by said pulse generating means by a time period from an instant that data is read out from one of said plurality of memory cells till said read means operates to complementary data.
Claim 19
Dependent Claim 51 words
A static random access memory according to claim 10, in which said pulse extension means extends the pulse width of the pulse signal generated by said pulse generating means, and inverts a logical state of the extended pulse signal with respect to the pulse signal generated by said pulse generating means.

References Cited (Backward Citations)

US4608670A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-07-02 1994-01-01 1994-07-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-07-02 1998-01-01 1998-07-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-07-02 2002-01-01 2002-07-03 $7700.00 Window Closed / Lapsed

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